The variability of observed tropical cyclone (TC) activity (i.e., genesis, track, and landfall) in the western North Pacific (WNP) is examined in relation to the various categories of the Madden-Julian oscillation (MJO) during summer (June-September) for the period 1979-2004. The MJO categories are defined based on the empirical orthogonal function analysis of outgoing longwave radiation data.The number of TCs increases when the MJO-related convection center is located in the WNP. The axis of a preferable genesis region systematically shifts like a seesaw in response to changes in the large-scale environments associated with both the eastward and northward propagation of the MJO and the intraseasonal variability of the WNP subtropical high. Furthermore, the authors show that the density of TC tracks in each MJO category depends on the systematic shift in the main genesis regions at first order. Also, the shift is affected by the prevailing large-scale steering flows in each MJO category. When the MJO-related convection center is found in the equatorial Indian Ocean (the tropical WNP), a dense area of tracks migrates eastward (westward). The effects of extreme ENSO events and the variations occurring during ENSO neutral years are also examined.A statistical analysis of TC landfalls by MJO category is applied in seven selected subareas: the Philippines,

[1] Although land-water carbon (C) transport represents a critical link in the global C cycle, rare attempts have been made to compare hydrologic controls over storm pulses of dissolved organic C (DOC) and particulate organic C (POC) in mountainous watersheds. An immersible UV/Vis spectrophotometer was used to comparatively investigate the rapid storm responses of stream water DOC and POC in a small mountainous forested watershed in South Korea. High-frequency measurements at 5-min intervals during 42 hydrologic events, including monsoon storms and winter snowmelts, showed consistent patterns: POC concentrations were lower than DOC concentrations during base flow and small storm events but exceeded them during the peak flow periods of intense storm events. Although both the DOC and POC concentrations had hysteretic relationships with discharge, the POC concentrations showed larger increases and variations after crossing a threshold discharge on the rising limb of the storm hydrograph. Stronger responses to intense storms resulted in a disproportionately large export of POC at high flow, whereas a large portion of the total DOC flux was exported under prevailing low-flow conditions. The results demonstrate the potential of in situ optical measurements for investigating fine-resolution dynamics of the DOC and POC export during storm events. Stronger storm responses of the POC export compared to the limited response range of the DOC export suggest that erosion-induced POC export will become more important as a major pathway for the hydrologic soil C loss from mountainous watersheds in response to an increasing occurrence of extreme storm events.

The Geostationary Environment Monitoring Spectrometer (GEMS) is scheduled for launch in February 2020 to monitor air quality (AQ) at an unprecedented spatial and temporal resolution from a geostationary Earth orbit (GEO) for the first time. With the development of UV–visible spectrometers at sub-nm spectral resolution and sophisticated retrieval algorithms, estimates of the column amounts of atmospheric pollutants (O3, NO2, SO2, HCHO, CHOCHO, and aerosols) can be obtained. To date, all the UV–visible satellite missions monitoring air quality have been in low Earth orbit (LEO), allowing one to two observations per day. With UV–visible instruments on GEO platforms, the diurnal variations of these pollutants can now be determined. Details of the GEMS mission are presented, including instrumentation, scientific algorithms, predicted performance, and applications for air quality forecasts through data assimilation. GEMS will be on board the Geostationary Korea Multi-Purpose Satellite 2 (GEO-KOMPSAT-2) satellite series, which also hosts the Advanced Meteorological Imager (AMI) and Geostationary Ocean Color Imager 2 (GOCI-2). These three instruments will provide synergistic science products to better understand air quality, meteorology, the long-range transport of air pollutants, emission source distributions, and chemical processes. Faster sampling rates at higher spatial resolution will increase the probability of finding cloud-free pixels, leading to more observations of aerosols and trace gases than is possible from LEO. GEMS will be joined by NASA’s Tropospheric Emissions: Monitoring of Pollution (TEMPO) and ESA’s Sentinel-4 to form a GEO AQ satellite constellation in early 2020s, coordinated by the Committee on Earth Observation Satellites (CEOS).

Life course and cohort-related factors contribute to similarities across societies in network types and their associations with well-being. Korean-specific life course and socio-historical factors, however, may contribute to our unique findings about network types.

[1] This study investigates the changes in winter cold extreme events over East Asia in the present and future climates. Two distinct terms to indicate cold extreme events are analyzed: "cold day," which describes a temperature below a certain threshold value (e.g., simply cold weather), and "cold surge," which describes an abrupt temperature drop (e.g., relatively colder weather than a previous day). We analyze both observations and long-term climate simulations from 13 atmospheric and oceanic coupled global climate models (CGCMs). The geographical distribution of sea level pressure corresponding to a cold day (cold surge) is represented by a dipole (wave train) feature. Although cold day and cold surge show similar patterns of surface air temperature, they are induced by the out-of-phase sea level pressures. From the results of our analysis of a series of future projections for the mid and late twenty-first century using the 13 CGCMs, cold day occurrences clearly decrease with an increasing mean temperature (a correlation coefficient of −0.49), but the correlation between cold surge occurrences and the mean temperature is insignificant (a correlation coefficient of 0.08), which is supported by the same results in recent observation periods . Thus, it is anticipated that cold surge occurrences will remain frequent even in future warmer climate. This deduction is based on the future projections in which the change in the day-to-day temperature variability is insignificant, although the mean temperature shows significant increase. The present results suggest that living things in the future, having acclimatized to a warmer climate, would suffer the strong impact of cold surges, and hence the issue of vulnerability to cold surges should be treated seriously in the future.